ltspicethermistor
Hi I am trying to simulate Vishays thermistor: NTCLE413E2103F520L using LTSpice XVII. I am referring to Application note and the LTSpice model by them to simulate it.
When I am trying to run the model after making changes to the circuit (Symbol for an NTC Thermistor and Symbol for a TFPT RTD only), I receive an error:
I am not sure what I should do. Am I not suppose to change the parameters? Am I making a mistake while changing the model? Should there be further changes in the model to use it?
I guess that the obvious answer is that it doesn't really matter where the thermistor is placed as long as it is in close contact with the battery being charged, because the cell temperature will be uniform during charge.
I did search the net quite a lot for an answer, but could not find anything about thermistor placement in battery chargers at all. I could only find placement of thermistor in circuit (the schematics). The only reference I found about its physical placement was this: Build a USB Powered AA NiMH and NiCd Battery Charger.
The completed charger with one cell in place. The 2-cell holder was made by cutting the outer positions off of a 4-cell holder. Notice how the thermistor is installed so as to make physical contact with the cells being charged. A small heatsink keeps Q1 cool.
The red marking is where I understand the thermistor was placed, which corresponds to Position C in my picture.
Your circuit would just work as a square wave output if you tried to prototype it, as you are connecting the inverting input to GND and driving the non-inverting input with a couple of volts. In this configuration, you are using the open-loop gain which is very large and it will always saturate the output of the opamp.
I'm not sure if there is a problem in the SPICE model, but I know that trying to go out of the voltage range of the part is causing the simulation to crash.
Try the following circuit and let me know if it runs. It's just a buffer configuration. I also added some offset to the V1 sine wave so that the output will never go negative.
Good luck!
Best Answer
This particular P/N is not included in the library yet . It has the same characteristics as NTCLE101E3C90173 though. So if you are not concnerned about self heating, you can use this other P/N iso NTCLE413E2103F520L. If you open the library in LT spice you will see all the P/N included in this library. Not all the P/N are included